The disclosure relates to a wireless power transmission technology. In more particular, a wireless power receiver, capable of maximizing the power transmission efficiency in power transmission, and a method of managing the power thereof.
A wireless power transmission or a wireless energy transfer refers to a technology of wirelessly transferring electric energy to desired devices. In the 1800's, an electric motor or a transformer employing the principle of electromagnetic induction has been extensively used and then a method for transmitting electrical energy by irradiating electromagnetic waves, such as radio waves or lasers, has been suggested. Actually, electrical toothbrushes or electrical razors, which are frequently used in daily life, are charged based on the principle of electromagnetic induction. The electromagnetic induction refers to a phenomenon in which voltage is induced so that current flows when a magnetic field is varied around a conductor. Although the commercialization of the electromagnetic induction technology has been rapidly progressed around small-size devices, the power transmission distance is short.
Until now, wireless energy transmission schemes include a remote telecommunication technology based on resonance and a short wave radio frequency in addition to the electromagnetic induction.
Recently, among wireless power transmitting technologies, an energy transmitting scheme employing resonance has been widely used.
In a wireless power transmission system employing resonance, since an electrical signal generated between the wireless power transmitter and the wireless power receiver is wirelessly transferred through coils, a user may easily charge electronic appliances such as a portable device.
However, as the typical wireless power receiver employs a DC-DC converter, the wireless power receiver may not overcome the problem related to the power transmission efficiency and the cost problem resulting from the size.